This invention relates generally to the field of antennas and, more specifically, to an end-fire cavity slot antenna array structure and method of forming.
Many type of antennas are in use today in aircraft. One such type of antenna is referred to as an end-fire cavity slot antenna array. An end-fire cavity slot antenna array typically includes a plurality of antenna elements having cavity slots that radiate radio frequency waves in the longitudinal direction of the slots. When used in an aircraft, an end-fire cavity slot antenna array structure is generally positioned on the wing. Because aerodynamic performance is important during the flight of an aircraft, these antennas and other antennas in use on aircraft are typically placed in radomes. These radomes consist of a radio frequency transparent shell so that the antenna is able to function properly, while maintaining sufficient aerodynamic properties for the aircraft. However, the parasitic nature of radomes, in which a shell or other housing is placed on an aircraft wing prevents aircraft designers from realizing improved aerodynamic conditions.
According to one embodiment of the invention, an end-fire cavity slot antenna array structure includes an upper skin formed from a composite material corresponding to a outer surface of an aircraft wing a lower skin formed from a composite material corresponding to a portion of an inner surface of the aircraft wing and a plurality of proximately positioned electrically conductive elements disposed between the upper and lower skins. Each electrically conductive element is formed from at least one sheet of composite material having an electrically conductive surface, and the sheet of composite material is configured such that the electrically conductive surface defines an inside surface of the electrically conductive element and any outside surfaces of the electrically conductive element that are in contact with an adjacent electrically conductive element.
According to another embodiment of the invention, a method of forming an end-fire cavity slot antenna array structure includes providing a plurality of tooling mandrels and forming a plurality of electrically conductive elements around the tooling mandrels. The electrically conductive elements are formed from at least one sheet of composite material having an electrically conductive surface configured such that the electrically conductive surface defines an inside surface of the electrically conductive element and any outside surfaces of the electrically conductive element that are in contact with an adjacent electrically conductive element. The method further includes positioning the electrically conductive elements proximate one another, disposing the electrically conductive elements between an upper skin and a lower skin, and curing the electrically conductive elements and the upper and lower skins.
Embodiments of the invention provide a number of technical advantages. Embodiments of the invention may include all, some, or none of these advantages. An end-fire cavity slot antenna array structure is provided that is load-bearingand conforms to the aerodynamic surface of an aircraft, which helps improve aerodynamic performance. A conformal antenna array structure eliminates the need for a radome. An end-fire cavity slot antenna array structure is formed form composite material such that a reflective surface exists on the inside surface of each electrically conductive element and an electrically conductive surface exists on the outside surface of the sides of the conductive elements so that a electrically conductive path exists between elements. Forming such a structure from such composite material results in structural continuity as well as radio frequency continuity.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.